Method for causing sprayed metal to adhere to metal surfaces



March 30, 1943. A. P. SHEPARD METHOD FOR CAUSING SPRAYED METAL TO ADHERE TO METAL SURFACES Original Filed July 27, 1938 Patented Mar. 30, 1943 r "UNIT-ED STATES Ar-E r OFFICE J METHOD roe CAUSING SPRAYED METAL 'ro ADHERE T METAL summons Arthur P. Shepard, New York, Y.,- assignor to Metallizing Engineering Company Inc Longi- IslamlCity, N. Y., a corporation of New Jersey Continuation of application Serial No, 366357, November 25, 1940, which isa division'of application Serial No. 221,650, July 127, 1 93 8. This application April 16, 1940, Serial no. 3295906- 3 Claims. .(Cl. 29-148) Thisinvention relates to a new and useful method for causing sprayed metal to adhere to metal surfaces. I

In industrial practice a coating of metal is frequently applied to a base of the same or other metal by spraying. For this purposethe'metal to be applied is melted and is projected as a spray against the surface to be covered. 'The applicaexample, be carried out to protect the base against corrosion, to provide a surface of the desired omation of sprayed metal in this manner may, for.

Fig.2-is a side view of a partof the construction shown ii'i'lfig. -1;' I 1- Fig. 3' is an enlarged edge view of a part of the construction shown in Fig. 2;

"Fig. 4 is a perspectiveview of a block of motor which has been'subjected to the'flrst stepof my method; I j

has been subjected to the firststep of my method;

Fig. 6'i's asection thiougl'rthe construction shown in Fig. 5 on the plane indicated by 6-6;

mental or bearing characteristics, or to build up 5 worn machine parts. In practice adhesion between the base and the sprayedmetal is obtained by preliminarily'grit-blasting the metal surface. In accordance with my method a higher and more" satisfactory adhesion is obtained without resort togrlt-blasting. In carrying out the method of my invention the roughem'ng of a given metal ibaseto be sprayed 7 upon is obtained by running thereon a plurality of circular rowsof teeth, the teeth of atleast' some of said rows being out of line with respect to the teeth of other rows until the' desired degree of roughness ,is obtained. Thethusly roughened surface does not show a succession of holes corre Fig.1"; is a section perpendicular to the grooves through-part of either the construction shown in Fig. 4 or iii-Fig. 5; o I

' Fig.'8is a corresponding section which has rei ceived the final'step of preparatory treatment in accordance with myinvention. v

Theinstrument or tool utilized in' the practice of my methodfcomprises-(Fig. 1) .a' group '1 or steel discs carried by spool 2 held by nut .I

and lock-nut 4 incontact with the spool and with one "another. Spool 2 and disc assembly I are spending to the form of the'teeth' since the teeth do not track or mesh in the surface ofithe work but, on the contrary, come down at random and in such a way that the surface betweenthe teeth marks first formed is splayed and peaned by subsequent impacts with'the teeth to form minute f cavities with overhanging outer edges. The base' to be sprayed upon is preferably secured in an appropriate metal working machine, such as a lathe or planer, depending upon the geometric form of the base. While the tool containin the circular rows of teeth as, for example, the tool hereinafter described in detail, is secured in the 'tool holder of the machine and runs upon the surface of the base to be covered. 1

A suitable instrument that may be utilized in the practice of my method is, for instance, the

one described and claimed in'my co-pending application, Serial No. 221,650, filed July 27, 1938 (continued as Serial No. 366,957, filed Nov. 25, 1940), of which the instant application is a division. 7

One illustrative embodiment of an instrument or tool useful in accordance with the invention,

as well as certain aspects and embodiments of my invention will be exemplified in the following.

description read in conjunction with the drawing in WhlCh- Fig. l is a cross-section through the tool;

carried by shaft. 5. s oi 2 is secured between shoulder fitintegralwith shaft 5' screw v7., By removing screw "I, spool I and disc assembly: 'Lmay be removed-from the shaft when desired and replace by a new spool and disc as- 3 sembly, Shaft 5 is' rotatably carried in'ballbearings l0 and I'l mountedin block 12 provided with extension s. 'l'hisextension isof" such size and proportions that it may be inserted and secured in theordinary lathe tool post or similarly v mounted in the tool holder of a machine tool a tool which"may be similarly manipulated by hand or secured in a machine tool post. The construction shown in Fig. 1 has, however, the advantage that if used on work which has aprojecting shoulder the disc assembly may be Worked closer to the shoulder than the alternative type in I which the disc assembly; is carried between the tynes of a forked handle. 7

Each of the discs 8 (Fig. 2') is provided with teeth 9, which teeth in a preferred construction,

.-'run about eighteen to the inch. The edges of each'tooth define'anangle of about from the vertex or point; The. teeth of the assembleddiscs are not in alignment but are staggered with respect to one another. .This is illustrated in Fig.

3 in which l5 designates the vertices of the teeth- Fig. 5 is a side viewof a cylindrical shape which I discs; while I1 designates-the vertices and I! the valleys between the teeth of the other discs.

As above pointed out, when using the tool as described in the practice of my invention, it is of of asuitable metal working machine and'to run the same over the surface of the metal work piece to be treated. Thus, for example, the disc shown in Fig. 4 could be treated in a machine with either a rotary or transitory motion between the tool and the work while the cylindrical shape shown in Figs. 5 and 6 wouldbe heat treated in 2,814,902 '7 and it the valleys between the teeth of alternate advantage to secure the: same in the tool holder 7 body of sprayedmetal which is locked in each groove by the dove-tailing and further adheres to the roughened remainder of the original surface to form a total bond or adhesion approaching the tensile strength of the sprayed metal itself. In so applyingthe sprayed metal the rounded contour of the bottom 25 of the grooving is of advantage since on the initial application the sprayed metal sticks more readily in the groove than would be the case if the grooving were formed with sharp corners or a flat floor.

a machine with a rotary motion-between the tool and the work.

While in many cases (a satisfactorydegree of attachment can be obtainedpythe steps here inabove described, I have found, that a'still high er attachment or bond between-the sprayed metal and the base is obtained by the additional steps hereinafter described. In accordance with this phaseof my invention surface 20 of disc 2| '(Fig. 4) has been sovtreated that a great number of small grooves "have been formed therein. In

the preferred practice these grooves are approximately 1 ,wide and the upstandingteethor ridges left between the grooves arefapproximately In depth the grooves may, for ex-V Where the bottom of the grooving is of rounded contour, moreover, there is a relative absence of bridgi g of the sprayed metal which would result in cavities.

The foregoing description is for purposes of iilustration and not of limitation, and it is there-- fore my intention thatvthe invention be limited only by the appended claims or their equivalents, wherein I have endeavored to claim broadly all inherent novelty.

I claim: r V 1. In the process of forming. by metal spray-l ing, an adherent coating of metal on a metal ample, range from to fi'r'. The bottoms of thegrooves may have any desired'contour but in the preferred practice thebottoms 2| (Fig. '7' and Fig.8) of the grooves 18 are of roimded con- 7 tom, while'the sides I! of, the grooves adjacent V 1 the remainder ofthe original surface-are substantially normal'to surfacel ll. ,I--lgs.:5 and 6 illustrate a cylindrical shape 2! whichhas been similarly prepared. In this case the grooves may either be formed as separate circular cuts formed, for example, by. the lathe tool, or, as one continuous hel x formedby cuttingfa spiral thread in the surface themethod of preparing such surface which comprises providing strolling tool having a plurality of circular rows of metal splaying and peening teeth, the teeth of at least some of said rows being out of line with respect to the teeth of otherrows, rolling such metal surface with such tool to cut irregularly spaced teeth marks,

simulating grit blasted marks, into said surface, continuing the rolling of the thusly cut surface with such tool and cause some'of saidteeth to mesh with previously cut teeth marks and other teeth to splay and peen out of mesh with previously cut teeth marks to thereby obtain a surface simulating a gritblasted surface.

surface of the cylindrical shape. Since in either case the result is to forms large number of grooves in the surface though in the latter cases I the grooves maybe the parts of one continuous spiral, this construction may be hereinafter referred to as forming. a number of grooves.

After the grocvinghas been formed, the remain- 2. In the process of forming, by metal spraying, anadherent coating of metal on a metal surface, the method of preparing such surface which comprises providing a rolling tool having a plurality of circular rows of metal splaying and peening teeth, theteeth of at least some of said 'rows being out of line with respect to the teeth of other rows, forming a multiple number of V closely spaced grooves in such metal surface,

der of the original surface is then operated upon i V withthe, tool illustrated in Figs. 1,2 and 3 until this remainder ofv the original surface has become roughened to such an extent that the sprayed] metal will adhere; preferably, h'owever the'remainder of the original surface has received such treatment by this tool that it is'peaned over and proiectsoverthe original limits of the grooving and this construction is illustrated in Fig. 8. Preferably-the width' of theoriginal surface-between grooves after peaning is approximately equal to the width of the intervening vspace.

.When such a surface issprayed on, the sprayed metal builds up within the grooving to form a 'repetitiously rolling the grooved metal ,witnsuch toolto cut irregularly spaced teeth marks, simulating grit-blasted marks,into said surface intermediate said grooves, continuing the rolling'of the thusly cut surface withsuch tool and cause some'of said'teeth to mesh with previously cut teeth marks and otherteeth to splay and peen out of mesh with previously cut teeth marks to thereby obtain .a surface, intermediate I said grooves, simulating a grit-blasted surface 3. The method in accordance with claim 2 in which the bottoms of the said grooves are formed in said base with rounded cross-section.

ARTHUR P. SHEPARD. 

